1. Field of the Invention
The invention relates to an apparatus for separating and removing integrated circuit chips from circuit boards and for replacing the integrated circuit chips, and more particularly, the invention relates to a system including a heating device for generating a flow of heated air, a circuit board holder for positioning a circuit board during chip removal, and a auxiliary preheater for heating the circuit board.
2. Brief Description of the Related Art
Hot gas desoldering tools are known for removing integrated circuit chips from circuit boards. Generally these tools direct a jet of hot gas at a component to melt the solder which connects the component leads to the circuit board. However, these known tools have a tendency to melt or otherwise damage the component being removed, the surrounding components, or the circuit board by overheating. These known desoldering tools have the additional disadvantage that they are difficult to adjust to a proper location and temperature and are generally difficult to use.
Integrated circuit chips that are to be removed may be traditional dual inline packages (DIP) with metal leads protruding from two sides, may have leads extending from all sides, or may be surface mount devices. Surface mount devices have leads at the perimeter of the device which are flush with the bottom surface of the device. Surface mount devices may also have connection points in the form of conductive pads on a bottom surface of the device allowing connection to the circuit board directly under the component. These surface mount devices allow the components to be more compact but are more difficult to remove without damage. It is desirable to be able to remove a variety of different component sizes and types with a single desoldering tool. Therefore, tools are provided with interchangeable nozzles for accommodating different chips. However, known tools with different nozzles do not provide systems for easily interchanging the nozzles even when hot. Accordingly, it would be desirable to provide a system of interchangeable nozzles which are easy to change.
Desoldering tools also may include a suction removal system for lifting a component off of the circuit board after the solder has been melted. However, these suction systems must be manually advanced into contact with the component risking component damage and adding an additional step for the user. Accordingly, it would be desirable to provide a fully automatic suction removal system for lifting a desoldered component off of a circuit board.
It would also be desirable to provide a system for desoldering which is easy to use, prevents damage to the circuit board or components, and easily accommodates components and circuit boards of different sizes and types.